The majority of four-wheel drive type vehicles employ a front driving axle having a wheel hub into which the clutch mechanism is subsequently assembled. The clutch mechanism typically is assembled within that portion of the wheel hub extending outwardly beyond the vehicle wheel. First, the clutch mechanism body subassembly is inserted into the wheel hub to internal wheel hub splines with mutually complementary splines on the exterior of the body subassembly. After the body subassembly is engaged to the wheel hub, lock rings or the like, are inserted around the inside surface of the wheel hub adjacent the body subassembly both to secure the body subassembly, and to prevent axial movement of the subassembly within the wheel hub. The remaining subassemblies of the clutch mechanism, including the mechanism which locks and unlocks the vehicle axle to the vehicle hub, are next inserted and assembled within the wheel hub. Finally, the clutch mechanism housing, such as a cap or the like, is secured to the wheel hub by means which are old per se, such as bolts, screws, or the like.
To repair the clutch mechanism, or to perform routine maintenance on the subassemblies, the clutch cap assembly first is removed to expose the clutch mechanism's subassemblies. For example, to repair the body subassembly, the cap is removed, and the mechanism which locks and unlocks the vehicle axle to the vehicle wheel is subsequently removed to expose the body subassembly lock rings. The lock rings are thereafter removed to access the body subassembly. This process can be time-consuming, since the lock rings or snap rings have to be pried out of engagement with the wheel hub by the use of small, sharp-pointed instruments such as screwdrivers or the like. Repair is further complicated since the snap rings are tightly secured within the wheel hub, in small and confining spaces.
Four-wheel drive vehicle manufacturers are interested in clutch mechanisms which allow simple and quick insertion into the vehicle front driving axles at the place of vehicle manufacture. In essence, the vehicle manufacturers would like to integrate the assembly of the locking clutch with their assembly of the vehicle. It is therefore desirable that the clutch mechanism, and its associated housing be preassembled so that the assembly of the mechanism with the vehicle front driving axle can be quick and simple, with the clutch mechanism having minimal susceptibility to being damaged or otherwise rendered inoperable during integration and assembly with the vehicle.
The present invention provides a clutch housing, including a preassembled clutch mechanism operable to lock and unlock the vehicle front driving axle to the vehicle wheel hub, which is specifically adapted for assembly to a four-wheel drive type vehicle front driving axle in a one step operation. By utilizing a compressible lock ring having an outside diameter slightly larger than the inside diameter of the vehicle wheel hub disposed around the clutch housing, the clutch housing of the present invention in inserted within the wheel hub to engage the lock ring to the wheel hub. When the lock ring is engaged, the clutch housing, including the preassembled clutch mechanism, is secured to the vehicle front driving axle. For removal to facilitate repair or the like, the cap screws securing a cover or clutch cap to the vehicle wheel hub are removed. The clutch cap is subsequently withdrawn allowing the compressible lock ring to have a diameter slightly smaller than the inside diameter of the wheel hub. The remainder of the clutch mechanism subassemblies may then be withdrawn in one piece with the locking ring of the present invention.